Heat dissipation apparatus and method

Abstract

A heat dissipation apparatus (51) has a lid (12) and an optimized fin arrangement (16) located in a cavity (57) of a base (11). Semiconductor chips (41, 42, 43, 44, 45, and 46) are coupled to the lid (12), and a heat conducting medium (47) is forced into the cavity (57) through a port (13) and out of the cavity (57) through a different port (14). Heat generated by the semiconductor chips (41, 42, 43, 44, 45, and 46) is thermally conducted into the fin arrangement (16) and then transferred into the heat conducting medium (47).

We claim: 
     
       1. A heat dissipation apparatus comprising: a lid;   a base underlying the lid, the lid and the base forming a cavity, the base having an input port, an output port, and further comprising: a first fin structure having a first sidewall surface area, physically contacting the lid, and located in the cavity and adjacent to the input port; and   a second fin structure having a second sidewall surface area, physically contacting the lid, and located in the cavity and adjacent to the output port, wherein the second sidewall surface area is greater than the first sidewall surface area, and wherein the first and second fin structures are approximately the same height;     a first semiconductor chip overlying the lid and overlying and thermally coupled to the first fin structure;   a second semiconductor chip overlying the lid and overlying and thermally coupled to the second fin structure; and   a guidance fin located in the cavity, wherein the guidance fin is substantially devoid of heat transfer from the first and second semiconductor chips.   
     
     
       2. The heat dissipation apparatus according to claim 1 wherein the first and second fin structures are integrated into the base. 
     
     
       3. The heat dissipation apparatus according to claim 1 wherein the first fin structure is wider than the first semiconductor chip. 
     
     
       4. The heat dissipation apparatus according to claim 1 wherein a temperature of the first semiconductor chip and a temperature of the second semiconductor chip are substantially equal. 
     
     
       5. The heat dissipation apparatus according to claim 1 wherein the lid and the base are comprised of a metal matrix composite. 
     
     
       6. A semiconductor module comprising: a lid;   a base underlying the lid, the lid and the base forming a cavity, the base having an input port, an output port, and further comprising: a first fin structure having a first sidewall surface area and located in the cavity and adjacent to the input port; and   a second fin structure having a second sidewall surface area and located in the cavity and adjacent to the output port, wherein the second sidewall surface area is greater than the first sidewall surface area, and wherein the input port and output port form a first axis;     a first semiconductor chip overlying the lid and overlying and thermally coupled to the first fin structure;   a second semiconductor chip overlying the lid and overlying and thermally coupled to the second fin structure; and   a third fin structure located in the cavity and located adjacent to the first fin structure, the input port located closer to the third fin structure than the first fin structure, the third fin structure having a third sidewall surface area less than the first sidewall surface area, an the first and third fin structures forming a second axis non-parallel to the first axis.   
     
     
       7. The semiconductor module of claim 6 wherein the second axis is approximately perpendicular to the first axis. 
     
     
       8. The semiconductor module of claim 7 wherein the second and third fin structures form a third axis approximately parallel to the first axis. 
     
     
       9. The semiconductor module of claim 6 further comprising a guidance fin located in the cavity, wherein the guidance fin is substantially devoid of heat transfer from the first and second semiconductor chips. 
     
     
       10. The semiconductor module of claim 6 further comprising a fourth fin structure located in the cavity and located adjacent to the second fin structure, the output port located closer to the second fin structure than the fourth fin structure, the fourth fin structure having a fourth sidewall surface area greater than the first, second, and third sidewall surface areas, wherein the second and fourth fin structures form a third axis non-parallel to the first axis. 
     
     
       11. The semiconductor module of claim 6 wherein the first, second, and third fin structures are approximately the same height. 
     
     
       12. The semiconductor module of claim 11 wherein the first, second, and third fin structures physically contact the lid. 
     
     
       13. A heat dissipation apparatus comprising: a lid;   a base underlying the lid, the lid and the base forming a cavity, the base having an input port, an output port, and further comprising: a first fin structure having a first sidewall surface area and located in the cavity and adjacent to the input port; and   a second fin structure having a second sidewall surface area and located in the cavity and adjacent to the output port, wherein the second sidewall surface area is greater than the first sidewall surface area, and wherein the first and second fin structures are approximately the same height;     a first semiconductor chip overlying the lid and overlying and thermally coupled to the first fin structure;   a second semiconductor chip overlying the lid and overlying and thermally coupled to the second fin structure; and   a third fin structure located in the cavity and located adjacent to the second fin structure, the output port located closer to the second fin structure than the third fin structure, the third fin structure having a third sidewall surface area greater than the second sidewall surface area and greater than the first sidewall surface area.   
     
     
       14. The semiconductor module of claim 13 further comprising a guidance fin located in the cavity, wherein the guidance fin is substantially devoid of heat transfer from the first and second semiconductor chips. 
     
     
       15. A heat dissipation apparatus comprising: a lid; and   a base coupled to the lid, the base having a cavity and further comprising: a first port;   a second port, wherein the cavity couples the first port and the second port;   a first fin structure having a first sidewall surface area and located in the cavity and adjacent to the first port;   a second fin structure having a second sidewall surface area and located in the cavity and adjacent to the second port, wherein the second sidewall surface area is greater than the first sidewall surface area;     a first semiconductor chip thermally coupled to and overlying the first fin structure so that heat from the first semiconductor chip is transferred to the first fin structure;   a second semiconductor chip thermally coupled to and overlying the second fin structure so that heat from the second semiconductor chip is transferred to the second fin structure; and   a guidance fin located in the cavity, wherein the guidance fin is substantially devoid of heat transfer from the first and second semiconductor chips.   
     
     
       16. A semiconductor module comprising: a first semiconductor chip;   a second semiconductor chip; and   a heatsink underlying the first and second semiconductor chips, the heatsink having a cavity with a height and coupling a first port and a second port and further comprised of: a first fin structure located in the cavity, located underneath and thermally coupled to the first semiconductor chip, having a first sidewall surface area, having the height of the cavity, and having a first top surface;   a second fin structure located in the cavity, located underneath and thermally coupled to the second semiconductor chip, having a second sidewall surface area less than the first sidewall surface area, having the height of the cavity, and having a second top surface, the first and second fin structures having approximately equal heights; and     a guidance fin located in the cavity, wherein the guidance fin is substantially devoid of heat transfer from the first and second semiconductor chips.   
     
     
       17. The semiconductor module according to claim 16 wherein the first fin structure is comprised of a plurality of fins, each of the plurality of fins having a top surface and a sidewall surface area, wherein the first sidewall surface area is comprised of the sidewall surface areas of the plurality of fins, and wherein the first top surface is comprised of the top surfaces of the plurality of fins. 
     
     
       18. The semiconductor module according to claim 16 further comprising a heat conducting medium flowing into the first port, through the cavity, and out of the second port, wherein the first and second sidewall surface areas are approximately parallel to an overall path of the heat conducting medium flowing through the cavity, wherein heat generated by the first semiconductor chip is dissipated from the first semiconductor chip into the first top surface, out of the first sidewall surface area, and into the heat conducting medium, and wherein heat generated by the second semiconductor chip is dissipated from the second semiconductor chip into the second top surface, out of the second sidewall surface area, and into the heat conducting medium. 
     
     
       19. The semiconductor module according to claim 16 wherein a difference in temperature between the first fin structure and the second fin structure is less than approximately five degrees Celcius. 
     
     
       20. The semiconductor module according to claim 16 wherein the heatsink is comprised of a hollow metal matrix composite structure.